Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * hugetlbpage-backed filesystem. Based on ramfs. | |
3 | * | |
4 | * William Irwin, 2002 | |
5 | * | |
6 | * Copyright (C) 2002 Linus Torvalds. | |
7 | */ | |
8 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/thread_info.h> | |
11 | #include <asm/current.h> | |
12 | #include <linux/sched.h> /* remove ASAP */ | |
13 | #include <linux/fs.h> | |
14 | #include <linux/mount.h> | |
15 | #include <linux/file.h> | |
16 | #include <linux/writeback.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/highmem.h> | |
19 | #include <linux/init.h> | |
20 | #include <linux/string.h> | |
21 | #include <linux/backing-dev.h> | |
22 | #include <linux/hugetlb.h> | |
23 | #include <linux/pagevec.h> | |
24 | #include <linux/quotaops.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/dnotify.h> | |
27 | #include <linux/statfs.h> | |
28 | #include <linux/security.h> | |
29 | ||
30 | #include <asm/uaccess.h> | |
31 | ||
32 | /* some random number */ | |
33 | #define HUGETLBFS_MAGIC 0x958458f6 | |
34 | ||
35 | static struct super_operations hugetlbfs_ops; | |
36 | static struct address_space_operations hugetlbfs_aops; | |
37 | struct file_operations hugetlbfs_file_operations; | |
38 | static struct inode_operations hugetlbfs_dir_inode_operations; | |
39 | static struct inode_operations hugetlbfs_inode_operations; | |
40 | ||
41 | static struct backing_dev_info hugetlbfs_backing_dev_info = { | |
42 | .ra_pages = 0, /* No readahead */ | |
43 | .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, | |
44 | }; | |
45 | ||
46 | int sysctl_hugetlb_shm_group; | |
47 | ||
2e9b367c AL |
48 | static void huge_pagevec_release(struct pagevec *pvec) |
49 | { | |
50 | int i; | |
51 | ||
52 | for (i = 0; i < pagevec_count(pvec); ++i) | |
53 | put_page(pvec->pages[i]); | |
54 | ||
55 | pagevec_reinit(pvec); | |
56 | } | |
57 | ||
58 | /* | |
59 | * huge_pages_needed tries to determine the number of new huge pages that | |
60 | * will be required to fully populate this VMA. This will be equal to | |
61 | * the size of the VMA in huge pages minus the number of huge pages | |
62 | * (covered by this VMA) that are found in the page cache. | |
63 | * | |
64 | * Result is in bytes to be compatible with is_hugepage_mem_enough() | |
65 | */ | |
8d3d81cf | 66 | static unsigned long |
2e9b367c AL |
67 | huge_pages_needed(struct address_space *mapping, struct vm_area_struct *vma) |
68 | { | |
69 | int i; | |
70 | struct pagevec pvec; | |
71 | unsigned long start = vma->vm_start; | |
72 | unsigned long end = vma->vm_end; | |
73 | unsigned long hugepages = (end - start) >> HPAGE_SHIFT; | |
74 | pgoff_t next = vma->vm_pgoff; | |
75 | pgoff_t endpg = next + ((end - start) >> PAGE_SHIFT); | |
76 | ||
77 | pagevec_init(&pvec, 0); | |
78 | while (next < endpg) { | |
79 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) | |
80 | break; | |
81 | for (i = 0; i < pagevec_count(&pvec); i++) { | |
82 | struct page *page = pvec.pages[i]; | |
83 | if (page->index > next) | |
84 | next = page->index; | |
85 | if (page->index >= endpg) | |
86 | break; | |
87 | next++; | |
88 | hugepages--; | |
89 | } | |
90 | huge_pagevec_release(&pvec); | |
91 | } | |
92 | return hugepages << HPAGE_SHIFT; | |
93 | } | |
94 | ||
1da177e4 LT |
95 | static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
96 | { | |
97 | struct inode *inode = file->f_dentry->d_inode; | |
2e9b367c AL |
98 | struct address_space *mapping = inode->i_mapping; |
99 | unsigned long bytes; | |
1da177e4 LT |
100 | loff_t len, vma_len; |
101 | int ret; | |
102 | ||
103 | if ((vma->vm_flags & (VM_MAYSHARE | VM_WRITE)) == VM_WRITE) | |
104 | return -EINVAL; | |
105 | ||
106 | if (vma->vm_pgoff & (HPAGE_SIZE / PAGE_SIZE - 1)) | |
107 | return -EINVAL; | |
108 | ||
109 | if (vma->vm_start & ~HPAGE_MASK) | |
110 | return -EINVAL; | |
111 | ||
112 | if (vma->vm_end & ~HPAGE_MASK) | |
113 | return -EINVAL; | |
114 | ||
115 | if (vma->vm_end - vma->vm_start < HPAGE_SIZE) | |
116 | return -EINVAL; | |
117 | ||
2e9b367c AL |
118 | bytes = huge_pages_needed(mapping, vma); |
119 | if (!is_hugepage_mem_enough(bytes)) | |
120 | return -ENOMEM; | |
121 | ||
1da177e4 LT |
122 | vma_len = (loff_t)(vma->vm_end - vma->vm_start); |
123 | ||
124 | down(&inode->i_sem); | |
125 | file_accessed(file); | |
126 | vma->vm_flags |= VM_HUGETLB | VM_RESERVED; | |
127 | vma->vm_ops = &hugetlb_vm_ops; | |
128 | ||
129 | ret = -ENOMEM; | |
130 | len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT); | |
131 | if (!(vma->vm_flags & VM_WRITE) && len > inode->i_size) | |
132 | goto out; | |
133 | ||
4c887265 AL |
134 | ret = 0; |
135 | hugetlb_prefault_arch_hook(vma->vm_mm); | |
1da177e4 LT |
136 | if (inode->i_size < len) |
137 | inode->i_size = len; | |
138 | out: | |
139 | up(&inode->i_sem); | |
140 | ||
141 | return ret; | |
142 | } | |
143 | ||
144 | /* | |
508034a3 | 145 | * Called under down_write(mmap_sem). |
1da177e4 LT |
146 | */ |
147 | ||
148 | #ifdef HAVE_ARCH_HUGETLB_UNMAPPED_AREA | |
149 | unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
150 | unsigned long len, unsigned long pgoff, unsigned long flags); | |
151 | #else | |
152 | static unsigned long | |
153 | hugetlb_get_unmapped_area(struct file *file, unsigned long addr, | |
154 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
155 | { | |
156 | struct mm_struct *mm = current->mm; | |
157 | struct vm_area_struct *vma; | |
158 | unsigned long start_addr; | |
159 | ||
160 | if (len & ~HPAGE_MASK) | |
161 | return -EINVAL; | |
162 | if (len > TASK_SIZE) | |
163 | return -ENOMEM; | |
164 | ||
165 | if (addr) { | |
166 | addr = ALIGN(addr, HPAGE_SIZE); | |
167 | vma = find_vma(mm, addr); | |
168 | if (TASK_SIZE - len >= addr && | |
169 | (!vma || addr + len <= vma->vm_start)) | |
170 | return addr; | |
171 | } | |
172 | ||
173 | start_addr = mm->free_area_cache; | |
174 | ||
1363c3cd WW |
175 | if (len <= mm->cached_hole_size) |
176 | start_addr = TASK_UNMAPPED_BASE; | |
177 | ||
1da177e4 LT |
178 | full_search: |
179 | addr = ALIGN(start_addr, HPAGE_SIZE); | |
180 | ||
181 | for (vma = find_vma(mm, addr); ; vma = vma->vm_next) { | |
182 | /* At this point: (!vma || addr < vma->vm_end). */ | |
183 | if (TASK_SIZE - len < addr) { | |
184 | /* | |
185 | * Start a new search - just in case we missed | |
186 | * some holes. | |
187 | */ | |
188 | if (start_addr != TASK_UNMAPPED_BASE) { | |
189 | start_addr = TASK_UNMAPPED_BASE; | |
190 | goto full_search; | |
191 | } | |
192 | return -ENOMEM; | |
193 | } | |
194 | ||
195 | if (!vma || addr + len <= vma->vm_start) | |
196 | return addr; | |
197 | addr = ALIGN(vma->vm_end, HPAGE_SIZE); | |
198 | } | |
199 | } | |
200 | #endif | |
201 | ||
202 | /* | |
203 | * Read a page. Again trivial. If it didn't already exist | |
204 | * in the page cache, it is zero-filled. | |
205 | */ | |
206 | static int hugetlbfs_readpage(struct file *file, struct page * page) | |
207 | { | |
208 | unlock_page(page); | |
209 | return -EINVAL; | |
210 | } | |
211 | ||
212 | static int hugetlbfs_prepare_write(struct file *file, | |
213 | struct page *page, unsigned offset, unsigned to) | |
214 | { | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
218 | static int hugetlbfs_commit_write(struct file *file, | |
219 | struct page *page, unsigned offset, unsigned to) | |
220 | { | |
221 | return -EINVAL; | |
222 | } | |
223 | ||
1da177e4 LT |
224 | static void truncate_huge_page(struct page *page) |
225 | { | |
226 | clear_page_dirty(page); | |
227 | ClearPageUptodate(page); | |
228 | remove_from_page_cache(page); | |
229 | put_page(page); | |
230 | } | |
231 | ||
232 | static void truncate_hugepages(struct address_space *mapping, loff_t lstart) | |
233 | { | |
234 | const pgoff_t start = lstart >> HPAGE_SHIFT; | |
235 | struct pagevec pvec; | |
236 | pgoff_t next; | |
237 | int i; | |
238 | ||
239 | pagevec_init(&pvec, 0); | |
240 | next = start; | |
241 | while (1) { | |
242 | if (!pagevec_lookup(&pvec, mapping, next, PAGEVEC_SIZE)) { | |
243 | if (next == start) | |
244 | break; | |
245 | next = start; | |
246 | continue; | |
247 | } | |
248 | ||
249 | for (i = 0; i < pagevec_count(&pvec); ++i) { | |
250 | struct page *page = pvec.pages[i]; | |
251 | ||
252 | lock_page(page); | |
253 | if (page->index > next) | |
254 | next = page->index; | |
255 | ++next; | |
256 | truncate_huge_page(page); | |
257 | unlock_page(page); | |
258 | hugetlb_put_quota(mapping); | |
259 | } | |
260 | huge_pagevec_release(&pvec); | |
261 | } | |
262 | BUG_ON(!lstart && mapping->nrpages); | |
263 | } | |
264 | ||
265 | static void hugetlbfs_delete_inode(struct inode *inode) | |
266 | { | |
149f4211 CH |
267 | if (inode->i_data.nrpages) |
268 | truncate_hugepages(&inode->i_data, 0); | |
269 | clear_inode(inode); | |
270 | } | |
271 | ||
1da177e4 LT |
272 | static void hugetlbfs_forget_inode(struct inode *inode) |
273 | { | |
0b1533f6 CH |
274 | struct super_block *sb = inode->i_sb; |
275 | ||
276 | if (!hlist_unhashed(&inode->i_hash)) { | |
277 | if (!(inode->i_state & (I_DIRTY|I_LOCK))) | |
278 | list_move(&inode->i_list, &inode_unused); | |
279 | inodes_stat.nr_unused++; | |
280 | if (!sb || (sb->s_flags & MS_ACTIVE)) { | |
281 | spin_unlock(&inode_lock); | |
282 | return; | |
283 | } | |
284 | inode->i_state |= I_WILL_FREE; | |
1da177e4 | 285 | spin_unlock(&inode_lock); |
0b1533f6 CH |
286 | /* |
287 | * write_inode_now is a noop as we set BDI_CAP_NO_WRITEBACK | |
288 | * in our backing_dev_info. | |
289 | */ | |
290 | write_inode_now(inode, 1); | |
291 | spin_lock(&inode_lock); | |
292 | inode->i_state &= ~I_WILL_FREE; | |
293 | inodes_stat.nr_unused--; | |
294 | hlist_del_init(&inode->i_hash); | |
1da177e4 | 295 | } |
1da177e4 LT |
296 | list_del_init(&inode->i_list); |
297 | list_del_init(&inode->i_sb_list); | |
298 | inode->i_state |= I_FREEING; | |
299 | inodes_stat.nr_inodes--; | |
300 | spin_unlock(&inode_lock); | |
301 | if (inode->i_data.nrpages) | |
302 | truncate_hugepages(&inode->i_data, 0); | |
1da177e4 LT |
303 | clear_inode(inode); |
304 | destroy_inode(inode); | |
305 | } | |
306 | ||
307 | static void hugetlbfs_drop_inode(struct inode *inode) | |
308 | { | |
309 | if (!inode->i_nlink) | |
6b09b9df | 310 | generic_delete_inode(inode); |
1da177e4 LT |
311 | else |
312 | hugetlbfs_forget_inode(inode); | |
313 | } | |
314 | ||
315 | /* | |
316 | * h_pgoff is in HPAGE_SIZE units. | |
317 | * vma->vm_pgoff is in PAGE_SIZE units. | |
318 | */ | |
319 | static inline void | |
320 | hugetlb_vmtruncate_list(struct prio_tree_root *root, unsigned long h_pgoff) | |
321 | { | |
322 | struct vm_area_struct *vma; | |
323 | struct prio_tree_iter iter; | |
324 | ||
325 | vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) { | |
326 | unsigned long h_vm_pgoff; | |
1da177e4 LT |
327 | unsigned long v_offset; |
328 | ||
329 | h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT); | |
330 | v_offset = (h_pgoff - h_vm_pgoff) << HPAGE_SHIFT; | |
331 | /* | |
332 | * Is this VMA fully outside the truncation point? | |
333 | */ | |
334 | if (h_vm_pgoff >= h_pgoff) | |
335 | v_offset = 0; | |
336 | ||
508034a3 HD |
337 | unmap_hugepage_range(vma, |
338 | vma->vm_start + v_offset, vma->vm_end); | |
1da177e4 LT |
339 | } |
340 | } | |
341 | ||
342 | /* | |
343 | * Expanding truncates are not allowed. | |
344 | */ | |
345 | static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) | |
346 | { | |
347 | unsigned long pgoff; | |
348 | struct address_space *mapping = inode->i_mapping; | |
349 | ||
350 | if (offset > inode->i_size) | |
351 | return -EINVAL; | |
352 | ||
353 | BUG_ON(offset & ~HPAGE_MASK); | |
354 | pgoff = offset >> HPAGE_SHIFT; | |
355 | ||
356 | inode->i_size = offset; | |
357 | spin_lock(&mapping->i_mmap_lock); | |
358 | if (!prio_tree_empty(&mapping->i_mmap)) | |
359 | hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); | |
360 | spin_unlock(&mapping->i_mmap_lock); | |
361 | truncate_hugepages(mapping, offset); | |
362 | return 0; | |
363 | } | |
364 | ||
365 | static int hugetlbfs_setattr(struct dentry *dentry, struct iattr *attr) | |
366 | { | |
367 | struct inode *inode = dentry->d_inode; | |
368 | int error; | |
369 | unsigned int ia_valid = attr->ia_valid; | |
370 | ||
371 | BUG_ON(!inode); | |
372 | ||
373 | error = inode_change_ok(inode, attr); | |
374 | if (error) | |
375 | goto out; | |
376 | ||
377 | if (ia_valid & ATTR_SIZE) { | |
378 | error = -EINVAL; | |
379 | if (!(attr->ia_size & ~HPAGE_MASK)) | |
380 | error = hugetlb_vmtruncate(inode, attr->ia_size); | |
381 | if (error) | |
382 | goto out; | |
383 | attr->ia_valid &= ~ATTR_SIZE; | |
384 | } | |
385 | error = inode_setattr(inode, attr); | |
386 | out: | |
387 | return error; | |
388 | } | |
389 | ||
390 | static struct inode *hugetlbfs_get_inode(struct super_block *sb, uid_t uid, | |
391 | gid_t gid, int mode, dev_t dev) | |
392 | { | |
393 | struct inode *inode; | |
1da177e4 LT |
394 | |
395 | inode = new_inode(sb); | |
396 | if (inode) { | |
397 | struct hugetlbfs_inode_info *info; | |
398 | inode->i_mode = mode; | |
399 | inode->i_uid = uid; | |
400 | inode->i_gid = gid; | |
401 | inode->i_blksize = HPAGE_SIZE; | |
402 | inode->i_blocks = 0; | |
403 | inode->i_mapping->a_ops = &hugetlbfs_aops; | |
404 | inode->i_mapping->backing_dev_info =&hugetlbfs_backing_dev_info; | |
405 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; | |
406 | info = HUGETLBFS_I(inode); | |
407 | mpol_shared_policy_init(&info->policy); | |
408 | switch (mode & S_IFMT) { | |
409 | default: | |
410 | init_special_inode(inode, mode, dev); | |
411 | break; | |
412 | case S_IFREG: | |
413 | inode->i_op = &hugetlbfs_inode_operations; | |
414 | inode->i_fop = &hugetlbfs_file_operations; | |
415 | break; | |
416 | case S_IFDIR: | |
417 | inode->i_op = &hugetlbfs_dir_inode_operations; | |
418 | inode->i_fop = &simple_dir_operations; | |
419 | ||
420 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
421 | inode->i_nlink++; | |
422 | break; | |
423 | case S_IFLNK: | |
424 | inode->i_op = &page_symlink_inode_operations; | |
425 | break; | |
426 | } | |
427 | } | |
428 | return inode; | |
429 | } | |
430 | ||
431 | /* | |
432 | * File creation. Allocate an inode, and we're done.. | |
433 | */ | |
434 | static int hugetlbfs_mknod(struct inode *dir, | |
435 | struct dentry *dentry, int mode, dev_t dev) | |
436 | { | |
437 | struct inode *inode; | |
438 | int error = -ENOSPC; | |
439 | gid_t gid; | |
440 | ||
441 | if (dir->i_mode & S_ISGID) { | |
442 | gid = dir->i_gid; | |
443 | if (S_ISDIR(mode)) | |
444 | mode |= S_ISGID; | |
445 | } else { | |
446 | gid = current->fsgid; | |
447 | } | |
448 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, gid, mode, dev); | |
449 | if (inode) { | |
450 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
451 | d_instantiate(dentry, inode); | |
452 | dget(dentry); /* Extra count - pin the dentry in core */ | |
453 | error = 0; | |
454 | } | |
455 | return error; | |
456 | } | |
457 | ||
458 | static int hugetlbfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
459 | { | |
460 | int retval = hugetlbfs_mknod(dir, dentry, mode | S_IFDIR, 0); | |
461 | if (!retval) | |
462 | dir->i_nlink++; | |
463 | return retval; | |
464 | } | |
465 | ||
466 | static int hugetlbfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) | |
467 | { | |
468 | return hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0); | |
469 | } | |
470 | ||
471 | static int hugetlbfs_symlink(struct inode *dir, | |
472 | struct dentry *dentry, const char *symname) | |
473 | { | |
474 | struct inode *inode; | |
475 | int error = -ENOSPC; | |
476 | gid_t gid; | |
477 | ||
478 | if (dir->i_mode & S_ISGID) | |
479 | gid = dir->i_gid; | |
480 | else | |
481 | gid = current->fsgid; | |
482 | ||
483 | inode = hugetlbfs_get_inode(dir->i_sb, current->fsuid, | |
484 | gid, S_IFLNK|S_IRWXUGO, 0); | |
485 | if (inode) { | |
486 | int l = strlen(symname)+1; | |
487 | error = page_symlink(inode, symname, l); | |
488 | if (!error) { | |
489 | d_instantiate(dentry, inode); | |
490 | dget(dentry); | |
491 | } else | |
492 | iput(inode); | |
493 | } | |
494 | dir->i_ctime = dir->i_mtime = CURRENT_TIME; | |
495 | ||
496 | return error; | |
497 | } | |
498 | ||
499 | /* | |
500 | * For direct-IO reads into hugetlb pages | |
501 | */ | |
502 | static int hugetlbfs_set_page_dirty(struct page *page) | |
503 | { | |
504 | return 0; | |
505 | } | |
506 | ||
507 | static int hugetlbfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
508 | { | |
509 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); | |
510 | ||
511 | buf->f_type = HUGETLBFS_MAGIC; | |
512 | buf->f_bsize = HPAGE_SIZE; | |
513 | if (sbinfo) { | |
514 | spin_lock(&sbinfo->stat_lock); | |
515 | buf->f_blocks = sbinfo->max_blocks; | |
516 | buf->f_bavail = buf->f_bfree = sbinfo->free_blocks; | |
517 | buf->f_files = sbinfo->max_inodes; | |
518 | buf->f_ffree = sbinfo->free_inodes; | |
519 | spin_unlock(&sbinfo->stat_lock); | |
520 | } | |
521 | buf->f_namelen = NAME_MAX; | |
522 | return 0; | |
523 | } | |
524 | ||
525 | static void hugetlbfs_put_super(struct super_block *sb) | |
526 | { | |
527 | struct hugetlbfs_sb_info *sbi = HUGETLBFS_SB(sb); | |
528 | ||
529 | if (sbi) { | |
530 | sb->s_fs_info = NULL; | |
531 | kfree(sbi); | |
532 | } | |
533 | } | |
534 | ||
96527980 CH |
535 | static inline int hugetlbfs_dec_free_inodes(struct hugetlbfs_sb_info *sbinfo) |
536 | { | |
537 | if (sbinfo->free_inodes >= 0) { | |
538 | spin_lock(&sbinfo->stat_lock); | |
539 | if (unlikely(!sbinfo->free_inodes)) { | |
540 | spin_unlock(&sbinfo->stat_lock); | |
541 | return 0; | |
542 | } | |
543 | sbinfo->free_inodes--; | |
544 | spin_unlock(&sbinfo->stat_lock); | |
545 | } | |
546 | ||
547 | return 1; | |
548 | } | |
549 | ||
550 | static void hugetlbfs_inc_free_inodes(struct hugetlbfs_sb_info *sbinfo) | |
551 | { | |
552 | if (sbinfo->free_inodes >= 0) { | |
553 | spin_lock(&sbinfo->stat_lock); | |
554 | sbinfo->free_inodes++; | |
555 | spin_unlock(&sbinfo->stat_lock); | |
556 | } | |
557 | } | |
558 | ||
559 | ||
1da177e4 LT |
560 | static kmem_cache_t *hugetlbfs_inode_cachep; |
561 | ||
562 | static struct inode *hugetlbfs_alloc_inode(struct super_block *sb) | |
563 | { | |
96527980 | 564 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(sb); |
1da177e4 LT |
565 | struct hugetlbfs_inode_info *p; |
566 | ||
96527980 CH |
567 | if (unlikely(!hugetlbfs_dec_free_inodes(sbinfo))) |
568 | return NULL; | |
1da177e4 | 569 | p = kmem_cache_alloc(hugetlbfs_inode_cachep, SLAB_KERNEL); |
96527980 CH |
570 | if (unlikely(!p)) { |
571 | hugetlbfs_inc_free_inodes(sbinfo); | |
1da177e4 | 572 | return NULL; |
96527980 | 573 | } |
1da177e4 LT |
574 | return &p->vfs_inode; |
575 | } | |
576 | ||
1da177e4 LT |
577 | static void hugetlbfs_destroy_inode(struct inode *inode) |
578 | { | |
96527980 | 579 | hugetlbfs_inc_free_inodes(HUGETLBFS_SB(inode->i_sb)); |
1da177e4 LT |
580 | mpol_free_shared_policy(&HUGETLBFS_I(inode)->policy); |
581 | kmem_cache_free(hugetlbfs_inode_cachep, HUGETLBFS_I(inode)); | |
582 | } | |
583 | ||
584 | static struct address_space_operations hugetlbfs_aops = { | |
585 | .readpage = hugetlbfs_readpage, | |
586 | .prepare_write = hugetlbfs_prepare_write, | |
587 | .commit_write = hugetlbfs_commit_write, | |
588 | .set_page_dirty = hugetlbfs_set_page_dirty, | |
589 | }; | |
590 | ||
96527980 CH |
591 | |
592 | static void init_once(void *foo, kmem_cache_t *cachep, unsigned long flags) | |
593 | { | |
594 | struct hugetlbfs_inode_info *ei = (struct hugetlbfs_inode_info *)foo; | |
595 | ||
596 | if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == | |
597 | SLAB_CTOR_CONSTRUCTOR) | |
598 | inode_init_once(&ei->vfs_inode); | |
599 | } | |
600 | ||
1da177e4 LT |
601 | struct file_operations hugetlbfs_file_operations = { |
602 | .mmap = hugetlbfs_file_mmap, | |
603 | .fsync = simple_sync_file, | |
604 | .get_unmapped_area = hugetlb_get_unmapped_area, | |
605 | }; | |
606 | ||
607 | static struct inode_operations hugetlbfs_dir_inode_operations = { | |
608 | .create = hugetlbfs_create, | |
609 | .lookup = simple_lookup, | |
610 | .link = simple_link, | |
611 | .unlink = simple_unlink, | |
612 | .symlink = hugetlbfs_symlink, | |
613 | .mkdir = hugetlbfs_mkdir, | |
614 | .rmdir = simple_rmdir, | |
615 | .mknod = hugetlbfs_mknod, | |
616 | .rename = simple_rename, | |
617 | .setattr = hugetlbfs_setattr, | |
618 | }; | |
619 | ||
620 | static struct inode_operations hugetlbfs_inode_operations = { | |
621 | .setattr = hugetlbfs_setattr, | |
622 | }; | |
623 | ||
624 | static struct super_operations hugetlbfs_ops = { | |
625 | .alloc_inode = hugetlbfs_alloc_inode, | |
626 | .destroy_inode = hugetlbfs_destroy_inode, | |
627 | .statfs = hugetlbfs_statfs, | |
149f4211 | 628 | .delete_inode = hugetlbfs_delete_inode, |
1da177e4 LT |
629 | .drop_inode = hugetlbfs_drop_inode, |
630 | .put_super = hugetlbfs_put_super, | |
631 | }; | |
632 | ||
633 | static int | |
634 | hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig) | |
635 | { | |
636 | char *opt, *value, *rest; | |
637 | ||
638 | if (!options) | |
639 | return 0; | |
640 | while ((opt = strsep(&options, ",")) != NULL) { | |
641 | if (!*opt) | |
642 | continue; | |
643 | ||
644 | value = strchr(opt, '='); | |
645 | if (!value || !*value) | |
646 | return -EINVAL; | |
647 | else | |
648 | *value++ = '\0'; | |
649 | ||
650 | if (!strcmp(opt, "uid")) | |
651 | pconfig->uid = simple_strtoul(value, &value, 0); | |
652 | else if (!strcmp(opt, "gid")) | |
653 | pconfig->gid = simple_strtoul(value, &value, 0); | |
654 | else if (!strcmp(opt, "mode")) | |
655 | pconfig->mode = simple_strtoul(value,&value,0) & 0777U; | |
656 | else if (!strcmp(opt, "size")) { | |
657 | unsigned long long size = memparse(value, &rest); | |
658 | if (*rest == '%') { | |
659 | size <<= HPAGE_SHIFT; | |
660 | size *= max_huge_pages; | |
661 | do_div(size, 100); | |
662 | rest++; | |
663 | } | |
664 | size &= HPAGE_MASK; | |
665 | pconfig->nr_blocks = (size >> HPAGE_SHIFT); | |
666 | value = rest; | |
667 | } else if (!strcmp(opt,"nr_inodes")) { | |
668 | pconfig->nr_inodes = memparse(value, &rest); | |
669 | value = rest; | |
670 | } else | |
671 | return -EINVAL; | |
672 | ||
673 | if (*value) | |
674 | return -EINVAL; | |
675 | } | |
676 | return 0; | |
677 | } | |
678 | ||
679 | static int | |
680 | hugetlbfs_fill_super(struct super_block *sb, void *data, int silent) | |
681 | { | |
682 | struct inode * inode; | |
683 | struct dentry * root; | |
684 | int ret; | |
685 | struct hugetlbfs_config config; | |
686 | struct hugetlbfs_sb_info *sbinfo; | |
687 | ||
688 | config.nr_blocks = -1; /* No limit on size by default */ | |
689 | config.nr_inodes = -1; /* No limit on number of inodes by default */ | |
690 | config.uid = current->fsuid; | |
691 | config.gid = current->fsgid; | |
692 | config.mode = 0755; | |
693 | ret = hugetlbfs_parse_options(data, &config); | |
694 | ||
695 | if (ret) | |
696 | return ret; | |
697 | ||
698 | sbinfo = kmalloc(sizeof(struct hugetlbfs_sb_info), GFP_KERNEL); | |
699 | if (!sbinfo) | |
700 | return -ENOMEM; | |
701 | sb->s_fs_info = sbinfo; | |
702 | spin_lock_init(&sbinfo->stat_lock); | |
703 | sbinfo->max_blocks = config.nr_blocks; | |
704 | sbinfo->free_blocks = config.nr_blocks; | |
705 | sbinfo->max_inodes = config.nr_inodes; | |
706 | sbinfo->free_inodes = config.nr_inodes; | |
707 | sb->s_maxbytes = MAX_LFS_FILESIZE; | |
708 | sb->s_blocksize = HPAGE_SIZE; | |
709 | sb->s_blocksize_bits = HPAGE_SHIFT; | |
710 | sb->s_magic = HUGETLBFS_MAGIC; | |
711 | sb->s_op = &hugetlbfs_ops; | |
712 | sb->s_time_gran = 1; | |
713 | inode = hugetlbfs_get_inode(sb, config.uid, config.gid, | |
714 | S_IFDIR | config.mode, 0); | |
715 | if (!inode) | |
716 | goto out_free; | |
717 | ||
718 | root = d_alloc_root(inode); | |
719 | if (!root) { | |
720 | iput(inode); | |
721 | goto out_free; | |
722 | } | |
723 | sb->s_root = root; | |
724 | return 0; | |
725 | out_free: | |
726 | kfree(sbinfo); | |
727 | return -ENOMEM; | |
728 | } | |
729 | ||
730 | int hugetlb_get_quota(struct address_space *mapping) | |
731 | { | |
732 | int ret = 0; | |
733 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
734 | ||
735 | if (sbinfo->free_blocks > -1) { | |
736 | spin_lock(&sbinfo->stat_lock); | |
737 | if (sbinfo->free_blocks > 0) | |
738 | sbinfo->free_blocks--; | |
739 | else | |
740 | ret = -ENOMEM; | |
741 | spin_unlock(&sbinfo->stat_lock); | |
742 | } | |
743 | ||
744 | return ret; | |
745 | } | |
746 | ||
747 | void hugetlb_put_quota(struct address_space *mapping) | |
748 | { | |
749 | struct hugetlbfs_sb_info *sbinfo = HUGETLBFS_SB(mapping->host->i_sb); | |
750 | ||
751 | if (sbinfo->free_blocks > -1) { | |
752 | spin_lock(&sbinfo->stat_lock); | |
753 | sbinfo->free_blocks++; | |
754 | spin_unlock(&sbinfo->stat_lock); | |
755 | } | |
756 | } | |
757 | ||
758 | static struct super_block *hugetlbfs_get_sb(struct file_system_type *fs_type, | |
759 | int flags, const char *dev_name, void *data) | |
760 | { | |
761 | return get_sb_nodev(fs_type, flags, data, hugetlbfs_fill_super); | |
762 | } | |
763 | ||
764 | static struct file_system_type hugetlbfs_fs_type = { | |
765 | .name = "hugetlbfs", | |
766 | .get_sb = hugetlbfs_get_sb, | |
767 | .kill_sb = kill_litter_super, | |
768 | }; | |
769 | ||
770 | static struct vfsmount *hugetlbfs_vfsmount; | |
771 | ||
772 | /* | |
773 | * Return the next identifier for a shm file | |
774 | */ | |
775 | static unsigned long hugetlbfs_counter(void) | |
776 | { | |
777 | static DEFINE_SPINLOCK(lock); | |
778 | static unsigned long counter; | |
779 | unsigned long ret; | |
780 | ||
781 | spin_lock(&lock); | |
782 | ret = ++counter; | |
783 | spin_unlock(&lock); | |
784 | return ret; | |
785 | } | |
786 | ||
787 | static int can_do_hugetlb_shm(void) | |
788 | { | |
789 | return likely(capable(CAP_IPC_LOCK) || | |
790 | in_group_p(sysctl_hugetlb_shm_group) || | |
791 | can_do_mlock()); | |
792 | } | |
793 | ||
794 | struct file *hugetlb_zero_setup(size_t size) | |
795 | { | |
796 | int error = -ENOMEM; | |
797 | struct file *file; | |
798 | struct inode *inode; | |
799 | struct dentry *dentry, *root; | |
800 | struct qstr quick_string; | |
801 | char buf[16]; | |
802 | ||
803 | if (!can_do_hugetlb_shm()) | |
804 | return ERR_PTR(-EPERM); | |
805 | ||
806 | if (!is_hugepage_mem_enough(size)) | |
807 | return ERR_PTR(-ENOMEM); | |
808 | ||
809 | if (!user_shm_lock(size, current->user)) | |
810 | return ERR_PTR(-ENOMEM); | |
811 | ||
812 | root = hugetlbfs_vfsmount->mnt_root; | |
813 | snprintf(buf, 16, "%lu", hugetlbfs_counter()); | |
814 | quick_string.name = buf; | |
815 | quick_string.len = strlen(quick_string.name); | |
816 | quick_string.hash = 0; | |
817 | dentry = d_alloc(root, &quick_string); | |
818 | if (!dentry) | |
819 | goto out_shm_unlock; | |
820 | ||
821 | error = -ENFILE; | |
822 | file = get_empty_filp(); | |
823 | if (!file) | |
824 | goto out_dentry; | |
825 | ||
826 | error = -ENOSPC; | |
827 | inode = hugetlbfs_get_inode(root->d_sb, current->fsuid, | |
828 | current->fsgid, S_IFREG | S_IRWXUGO, 0); | |
829 | if (!inode) | |
830 | goto out_file; | |
831 | ||
832 | d_instantiate(dentry, inode); | |
833 | inode->i_size = size; | |
834 | inode->i_nlink = 0; | |
835 | file->f_vfsmnt = mntget(hugetlbfs_vfsmount); | |
836 | file->f_dentry = dentry; | |
837 | file->f_mapping = inode->i_mapping; | |
838 | file->f_op = &hugetlbfs_file_operations; | |
839 | file->f_mode = FMODE_WRITE | FMODE_READ; | |
840 | return file; | |
841 | ||
842 | out_file: | |
843 | put_filp(file); | |
844 | out_dentry: | |
845 | dput(dentry); | |
846 | out_shm_unlock: | |
847 | user_shm_unlock(size, current->user); | |
848 | return ERR_PTR(error); | |
849 | } | |
850 | ||
851 | static int __init init_hugetlbfs_fs(void) | |
852 | { | |
853 | int error; | |
854 | struct vfsmount *vfsmount; | |
855 | ||
856 | hugetlbfs_inode_cachep = kmem_cache_create("hugetlbfs_inode_cache", | |
857 | sizeof(struct hugetlbfs_inode_info), | |
858 | 0, 0, init_once, NULL); | |
859 | if (hugetlbfs_inode_cachep == NULL) | |
860 | return -ENOMEM; | |
861 | ||
862 | error = register_filesystem(&hugetlbfs_fs_type); | |
863 | if (error) | |
864 | goto out; | |
865 | ||
866 | vfsmount = kern_mount(&hugetlbfs_fs_type); | |
867 | ||
868 | if (!IS_ERR(vfsmount)) { | |
869 | hugetlbfs_vfsmount = vfsmount; | |
870 | return 0; | |
871 | } | |
872 | ||
873 | error = PTR_ERR(vfsmount); | |
874 | ||
875 | out: | |
876 | if (error) | |
877 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
878 | return error; | |
879 | } | |
880 | ||
881 | static void __exit exit_hugetlbfs_fs(void) | |
882 | { | |
883 | kmem_cache_destroy(hugetlbfs_inode_cachep); | |
884 | unregister_filesystem(&hugetlbfs_fs_type); | |
885 | } | |
886 | ||
887 | module_init(init_hugetlbfs_fs) | |
888 | module_exit(exit_hugetlbfs_fs) | |
889 | ||
890 | MODULE_LICENSE("GPL"); |